Weighing and charging mechanism for transit mix trucks



Oct. 16, 1951 c. D. CROSBY 2,571,113

WEIGHING AND CHARGING MECHANISM FOR TRANSIT MIX TRUCKS Filed Aug. 15, 1949- 2 Sheets-Sheet 1 4| 42 37 29 B 59 A 54 g I? 26 7 w i:

INVENTOR. F I Qhurles D. Cros y A I IORNEY C. D. CROSBY Oct. l6, 1951 WEIGHING AND CHARGING MECHEEISM FOR TRANSIT MIX TRUCKS 2 Sheets-Sheet 2 Filed Aug. 15, 1949 ATTORNF Patented Oct. 16, 1951 WEIGHING AND CHARGING MECHANISM FOR TRANSIT MIX TRUCKS Charles D. Crosby, Denver, Colo.

Application August 15, 1949, Serial No. 110,254

This invention relates to a self-loading, vehicle mounted materials mixer, and more particularly to a self-loading mobile cement mixer incorporating a weighing device for use with the loader to accurately predetermine the materials content of the mixed product.

In recent years the building and construction industries have quite widely recognized the advantages inherent in transit mix cement trucks which are adapted to mix cement while moving from a central loading point to the place of construction. Generally the mix obtainable through use of mobile mixing apparatus is better than that which may be economically obtained at the situs of the construction. Further there is a saving in time, labor and money inasmuch as the materials are mixed while being moved from a central point thereby eliminating at least one extra handling of the material and also fully utilizing the time spent in moving the material toward the job.

While the building and construction industries have widely accepted mobile mixers as efiicient units of their ordinary construction equipment, it has also been recognized that the expense of mixing the materials enroute increases in proportion to the distance that must be traveled by the truck between the time of loading and discharge. For really economic operation it has been found that the central loading plant should be within a five-mile radius of the work being accomplished and of course the closer the loading point is to the point of discharge, the more eflicient the operation is if the course traveled allows, time enough to thoroughly mix the products.

The present inventor has devised a self-loading attachment for transit mix trucks which makes it possible to have the loading point close to the point of discharge. Further the device of the present invention makes it possible for the cement contractor to operate without providing a relatively expensive aggregate and cement loading plant.

To accomplish the purposes mentioned above, the applicant provides construction equipment designated to satisfy among others, the following objects:

To provide vehicle mounted materials mixers for use at the construction site.

To provide a mixer of the foregoing type which may be loaded with materials near the construction site by means of self-loading apparatus attached to the vehicle.

T provide a vehicle mounted cement mixer 6 Claims. (Cl. 259 164) 2 which may be self loaded by the use of a front end loader operated by the driver of the vehicle.

To provide a loading attachment for vehicle mounted mixers which may be used to elevate the materials to be mixed from a position adjacent the vehicle supporting ground to a place of discharge into the materials mixer.

To provide hydraulically operated self-loading apparatus for attachment to a vehicle upon which a rotary drum type mixer is mounted, said loading apparatus being adapted to elevate the materials from a position in front of the vehicle to a position of discharge into the rotary drum mixer.

To provide apparatus for weighing materials being elevated by a self-loading attachment on vehicle mounted mixers during movement of the material from a position adjacent the vehicle supporting ground in front of the vehicle to an elevated position of discharge into the mixer.

To provide apparatus for weighing the amount of material being loaded by a vehicle mounted loader. I

Other objects and advantages of the present invention will be apparent from the appended description and drawings in which:

Fig. 1 is a side elevation of the device of this invention showing a loader attachment in the lowered loading position;

"Fig. 2 is a side elevation of the device of Fig. 1 showing the self-loading attachment in elevated position;

Fig. 3 is a side elevation of the device of Fig. 1 showing the self-loading attachment in the discharge position;

Fig. 4 is a side elevation showing in more complete detail the dumping operation depicted in Fig. 3; and

Fig. 5 is a rear elevation taken along the lin 5-5 of Fig. 2 further showing the features of this invention.

Briefly stated, the present invention provide a front loader attachment for vehicles which is particularly adapted for the loading of aggregate or other materials from a position adjacent the vehicle supporting surface to a dumping position above and behind the vehicle drivers station. The front end loader provided is particularly adapted to loading the necessary ingredients for concrete into a discharge hopper above a rotary drum type of cement mixer. To assure the eflicient operation of the loader, the applicant provides a hydraulic system for raising and lowering pivotally mounted arms which support a load carrying bucket. Since the device is intended to be operated by a single operator, the load carry- 3 ing bucket is designed to be self-dumping when it reaches the desired point of discharge.

In order to assure the proper proportions of aggregate and cement or of other types of mixing materials, the present device provides means for weighing the material being raised in the load carrying bucket. The means for accomplishing this purpose may either be through the use of electrical strain gages or by use of hydraulic pressure measuring apparatus calibrated to read in units of weight.

Referring now to the drawings, the features of a specific embodiment of this invention will be more fully described. In Fig. 1 it is shown that the applicant provides a vehicle ll of conventional type structure having a cab |2 housing an operators station, a power unit l3 for driving the wheels l4 and a load carrying frame l5 disposed behind the cab l2. suitably supported above the wheels M by springs H.

A rotary drum type of materials mixing apparatus is mounted above the frame H5 at a position behind the drivers cab |2. This mixing apparatus is of conventional design and accordingly consists of a rotary drum l8 mounted for rotation at a slight angle of inclination with respect to the frame l6 and suitably interconnected as by gears or chain drive (not shown) to an auxiliary power unit l9 which is used to cause rotation of the drum l8. Other conventional accessories such as a water supply tank 2| and discharge chutes 22 are provided, The rotary drum itself is preferably of a design having mixing vanes within the drum l8 adapted to mix the materials introduced into the drum when the drum is rotated in a first direction, and to auger the material out of the drum when the drum is rotated in an opposite direction.

As modifications on the drum itself the applicant provides a manhole type opening (not shown) in the surface of the drum which may be readily opened or closed by the driver-operator when it is desired to introduce a charge into the rotary drum |8 for mixing. The opening is so placed on the drum surface that it will be in registration with the downwardly extending spout 23 of the material receiving hopper 24 mounted above the drum when the drum I8 is rotated to place the opening in an upright position.

As a further modification of present type equipment the applicant provides a hydraulically operated loading mechanism which is mounted for pviotal movement about shaft 26 attached to the frame l6 by means of braces 21 and the like.

The loading mechanism itself is made up of two forwardly extending arms 28 mounted on the opposite sides of the vehicle The arms 28 when in their lowered position are alongside of the forward end of the vehicle II and they extend beyond the front bumper 29 of the vehicle A hydraulic mechanism consisting of a cylinder 3| having a reciprocal piston 32 mounted for longitudinal movement therein is pivotally mounted on the vehicle H and secured to the frame Is by pivot pin 33. Suitable flexible tubing 34 interconnects the hydraulic cylinder 3| with a hydraulic pump (not shown) which may be driven by the vehicle power unit l3 or the auxiliary power unit l9. Preferably the auxiliary power unit |.9 should be used for pumping the hydraulic fluid under pressure into the cylinder 3|.

The piston 32. is pivotally secured by means of a pin 38 to a brace 39 which is itself rigidly affixed to the arm 28 as by welding or the like.

Another member 4| likewise rigidly afiixed to the arm 28 provides support for a shoe member 42. By means of this combined arrangement of parts, the application of hydraulic pressure causing the shaft 32 to move inwardly toward the cylinder 3| causes the arms 28 to be raised from the lower position adjacent to and approximately parallel with the ground to an elevated position adjacent to the hopper 24.

It will be observed in the successive Figures 1, 2 and 3 that the force transmitted by the shaft 32 first acts through the link 3'. causing a force to be exerted against the shoe 42 as shown in Fig. 1, thereby tending to raise the arms, then a direct tensional force in the link 31 and brace 39 further tending to raise the arms. During the upward movement or" the arms 28, the cylinder 3| likewise moves to alternate positions which tend to keep the piston shaft 32 from binding in the cylinder 3|.

A load carrying member or bucket 43 which is of special design is supported between the arms 28 at opposite sides of the vehicle by means of trunnions 44. By reason of the use of the trunnions 44 bucket 43 is free to rotate through a small angle with respect to the arms 28, but such movement is of relatively limited extent. The bucket is provided with a forwardly disposed opening 45 which is bounded on the lower side of the bucket by a scraper member 41 and at the upper edge by an extension 48 which increases the load carrying capacity of the bucket. At the end of the bucket disposed away from the forwardly disposed opening 46 a discharge opening 49 is provided. This discharge opening 49 is normally closed by means of a conveyor plate 5| attached to the bucket 43 by means of arms 52 and the pivot pins 53. A spring 54 under initial tension tends to hold the conveyor plate 5| in a position closing the opening 49.

Since the bucket 43 is intended to be self-dumping, lateral extensions 55 are attached to the sides of the conveyor plate 5|. These extensions are so arranged that they will come into engagement with brackets 51 affixed to the hopper 24. After the brackets 51 are in contact with the extensions 56 further backward movement of the arms 28 and the bucket 43 causes the cover plate 5| to be moved away from the discharge opening 49 thereby dumping the contents of the bucket through the hopper 24, through the manhole opening, and into the rotary drum 58.

Since the bucket is self -dumping the driver operator may continue the loading operation from within the drivers cab. The successive steps of the operation will include moving the entire vehicle forward toward a pile of aggregate B2 or other material until the bucket 43 is completely filled. Since the bucket 43 is mounted for slight pivotal movement on trunnions 44, the ground or surface upon which the materials are dumped will be left relatively clean by this bucket charging operation. When the bucket 43 is completely filled, the driver can by manipulation of the lever 63 within the cab cause hydraulic fluid under pressure to be moved into the cylinder 3| in such manner as to effectively shorten the length of the piston shaft 32, thereby moving the loader arms 28 upwardly through the successive position shown in Figs. 2 and '3 to discharge additional material into the hopper 24 and thence into drum l8. After the material has been completely discharged the driver operator may then move the lever 63 in an opposite direction to cause the loader arms 28 to return to their normal position adjacent the vehicle supporting ground. The function of providing hydraulic fluid under pressure will not overload the auxiliary power unit l9, if this unit is used since the drum is not rotated but is held in fixed position throughout the drum charging operation.

When a full charge of materials has been introduced into the rotary drum it through the manhole opening which is maintained in its upright position by use of a locking or braking mechanism (not shown) the driver-operator can then close the manhole opening and engage the clutch of the auxiliary drive unit to rotate the drum [8 in the materials mixing direction. When the materials have been sufficiently intermixed, water or other liquid in the tank 2! may be introduced and the mixing operation continued as the driver moves the vehicle I from the loading point to the point of use. Since the materials mix rapidly, the distance between the loading point and the point of use need not be too great.

However, the distance or time of mixing for conmixed materials and discharge these materials down the chute 22 to the final position of use.

In the mixing of many products, it is essential that the proportions of ingredients be held within the prescribed engineering specifications. In

order to make exact mixtures possible, the an- 5,.

plicant further provides means for weighing the diiTerent types of materials hoisted by the charging bucket 43. The means utilized for weighing these materials can be of several different forms. In the drawings the applicant has illustrated the use of electrical strain gages 53 positioned along the loader arms 2%. These strain gages 5B are so aflixed to the arms 28 as to measure changed electrical resistance in accordance with changes in the tension forces within the arm 28. The electrical impulses resulting from such changed tension characteristics is carried by means of wires 59 to an indicator and calibrating mechanism 6! positioned within the drivers cab l2. When the instruments are properly calibrated so that the changes in electrical resistivity are indicated as units of weight, the driver by watching the indicator til and adding up the total weights of the materials hoisted can predetermine the exact proportion of ingredients which are introduced into the rotary drum 13. Accordingly through use of the weighing apparatus of this invention, the applicant provides means for mixing specification concrete or other materials without the previously necessary expenditure represented in purchasing a large batching plant with conventional type weighing apparatus.

While the applicant has shown the use of electrical strain gases. it will be apparent that alternate gages could be provided to measure the hydraulic pressure within the cylinders 3| and indicate changes in the pressure necessary to raise the arms 28 and bucket .3 in units of weight. Likewise other means and mechanisms could be employed to facilitate the weighing of the materials being loaded by the self-loading device of this invention.

While one specific embodiment of this invention has been shown and described, it will be apparent to those skilled in the art that many modifications and changes are possible without departing from the original idea of this invention. Accordingly all such changes and modifications as are within the scope of the hereunto appended claims are deemed to be part of this invention.

What is claimed is:

1. As a unit of construction equipment, a vehicle mounted on suitable traction devices having a main power unit for purposes of vehicle propulsion, a rotary drum mounted on the frame of said vehicle having an opening in said drum for the reception of bulk materials, power driven means for rotating said drum, a materials receiving hopper positioned above said drum having a discharge opening adapted for registration with the opening in said drum, loader arms pivotally mounted on said vehicle frame, a load carrying member supported by said arms for receiving and holding bulk materials having a discharge opening therein, a door pivotally mounted on said load carrying member adjacent said discharge opening for holding the bulk materials in said load carrying member when the door in closed position, a hydraulic cylinder having a piston member mounted for reciprocal movement therein, a hydraulic pump for introducing fluid under pressure into said cylinder, linkage mechanism interconnecting said piston and said loader arms so that the introduction of fluid under pressure to effectively shorten the exposed length of said piston causes upward movement of said arms and load carrying member from a position adjacent the vehicle supporting surface to a position adjacent said ho per, stop for engaging said door as the load carrying member is being moved toward its position in registration with said'hopper for holding the door in place as the load carrying member moves on to its position of registration with the hopper thereby d mping the contents of the load carrying member into the hopper.

2. As a unit of construction equipment, a vehicle mounted on suitable traction devices having a main power unit for purposes of vehicle propulsion, a rotary drum mounted on the frame of said vehicle having an opening in said drum for the reception. of bulk materials, power driven means for rotating said drum, a materials receiving hopper positioned above said drum having a discharge opening adapted for registration with the opening in said drum, loader arms pivotally mounted on said vehicle frame, a load carrying member supported by said arms for receiving and holding bulk materials, a hydraulic cylinder having a piston member mounted for reciprocal movement therein, a hydraulic pump driven by the means normally used for rotating said drum for introducing fluid under pressure into said cylinder, linkage mechanism interconnecting said piston and said loader arms so that the introduction of fluid under pressure to effectively shorten the exposed length of said piston causes upward movement of said arms and load carrying member from a position adjacent the vehicle supporting surface to a position adjacent said hopper, and means for automatically discharging the contents of said load member into said hopper when the load carrying member is disposed over said hopper.

3. As a unit of construction equipment, a vehicle mounted on suitable traction devices having a main power unit for purposes of vehicle propulsion, a rotary drum having an opening in a lateral side thereof mounted on the frame of said vehicle for rotation about a substantially horizontal axis,

7 power driven means for rotating said drum, loader arms pivotally mounted on said frame, a load carrying member supported by said arms having a forwardly disposed opening for the reception of bulk materials and a second opening therein for the discharge of said bulk materials, a door movably mounted on said load carrying member adjacent said discharge opening for holding the bulk materials in said load carrying member when the door is in the closed position, means for raising said arms to move said load carrying member from a position adjacent the vehicle supporting surface backwardly toward a position adjacent said drum opening, and stop means for engaging said door as the load carrying member is being moved toward its position in registration with said drum opening for holding said door in place as the load carrying member continues its backward movement whereby the bulk materials in said load carrying member are dumped through said .1

drum opening.

4. As a unit of construction equipment, a vehicle mounted on suitable traction devices having a main power unit for purposes of vehicle propulsion, a rotary drum having an opening therein mounted on the frame of said vehicle for rotation about a substantially horizontal axis, power driven means for rotating said drum, loader arms pivotally mounted on said frame, a load carrying member supported by said arms having a forwardly disposed opening for the reception of bulk materials and a second opening therein for the discharge of the bulk materials, a door movably mounted on said load carrying member adjacent the discharge opening for holding the bulk materials in said load carrying member when the door is in the closed position, a materials receiving hopper positioned above said drum having a discharge opening adapted for registration with the opening in said drum, means for raising said arms to move the load carrying member from a position adjacent the vehicle supporting surface backwardly toward a position adjacent said materials receiving hopper, and stop means for engaging said door as the load carrying member is being moved toward its position in registration with said hopper for holding said door in place as the load carrying member continues its backward movement thereby discharging the bulk materials into said I hopper.

5. As a unit of construction equipment, a vehicle mounted on suitable traction devices having a main power unit for purposes of vehicle propulsion, a rotary drum having an opening in a lateral side thereof mounted on the frame of said vehicle for rotation about a substantially horizontal axis, power driven means for rotating said drum, loader arms pivotally mounted on said frame, a load carrying member supported by said arms having a forwardly disposed opening for the reception of bulk materials and a second opening therein for the discharge of said bulk materials, a door movably mounted on said load carrying member adjacent said discharge opening for holding the bulk materials in said load carrying member when the door is in the closed position, hydraulic means for raising said arms to move said load carrying member from a position adjacent the vehicle supporting surface backwardly toward a position adjacent said drum opening, and stop means for engaging said door as the load carrying member is being moved toward its position in registration with said drum opening for holding said door in place as the load carrying member continues its backward movement whereby the bulk materials in said load carrying member are dumped through said drum opening.

6. As a unit of construction equipment, a vehicle mounted on suitable traction devices having a main power unit for purposes of vehicle propulsion, a rotary drum having an opening therein mounted on the frame of said vehicle for rotation about a substantially horizontal axis, power driven means for rotating said drum, loader arms pivotally mounted on said frame, a load carrying member supported by said arms having a forwardly disposed opening for the reception of bulk materials and a second opening therein for the discharge of the bulk materials, a door movably mounted on said load carrying member adjacent the discharge opening for holding the bulk materials in said load carrying member when the door is in the closed position, a materials receiving hopper positioned above said drum having a discharge opening adapted for registration with the opening in said drum, means for raising said arms to move the load carrying member from a position adjacent the vehicle supporting surface backwardly toward a position adjacent said materials receiving hopper, extension members on said door, cooperative stop members on said hopper for engaging the extension members on the door as the load carrying member is being moved toward its position of registration with said hopper for holding said door in place as the load carrying member continues its backward movement thereby dumping the bulk materials in said load carrying member into said hopper.

CHARLES D. CROSBY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,506,762 Mannierre Sept. 2, 1924 1,615,315 Shaw Jan. 25, 1927 1,781,965 Ball Nov. 18, 1930 2,276,125 Viall Mar. 10, 1942 2,327,473 Wagner et al. Aug. 24, 1943 

